Mr. W. H. Benson on new forms of Helix. 473 



The form and obliquity of the aperture differ in the two shells ; 

 and the ]Mergui species is deficient in the compression of the 

 base observable in the Moulmein shell. The same costulate 

 striation prevails, and the apical whorls are smooth in both spe- 

 cies. A single specimen of this very interesting form was ob- 

 tained. It increases the number of known Tenasserim species 

 to three. 



2. Helix Calias, B., n. s. 



Testa anguste umbilicata, orbiculato-depressa, oblique striatula, niti- 

 dula, pallida cornea ; spira planata, apice saliente, sutura margi- 

 nata, canaliculata, anfractibus 5 subconvexis, sensim accrescentibus, 

 ultimo ad ambitum rotundato, subtus convexiusculo ; apertura 

 lunata, subverticali, peristomate recto, acuto, tenui, margine colu- 

 mellari primo oblique, turn verticaliter descendente, calloso, superne 

 breviter expansiusculo, cum basali angulum fere rectum efformante, 

 eo carinam acutam horizontalem circum umbilicum perspectivum 

 ambientem, et spiraliter iutrantem, emittente. 



Diam. major 9, minor "g, axis 4 mill. 



Habitat prope Moulmein. 



Less than a month had elapsed from the date of my paper 

 announcing the peculiar formation of the columellar lip and 

 umbilicus in the Tenasserim Helix forabilis, B., when this shell 

 reached me by the overland route, presenting, with a very dif- 

 ferent form, the same characteristic pillar lip and horizontal 

 spiral keel at the umbilicus, on which I had so confidently relied 

 for the future recognition of that species when it might be met 

 with in a more perfect condition. The shell next to be described 

 offers a still more exaggerated development of the same type at 

 the basal angle; and, taken together, these shells may justly be 

 regarded as types of a peculiar Southern Burmese section of the 

 Naninoid group. In order to distinguish, it from the forms 

 named by Albers, Pfeiffer, and others, this section may, with the 

 following characters, be designated by the term 



SophinOy B. 



Testa Nauinoidea ; columella callosa, declivis, cum margine basali 

 angulum efformans, angulo, nonnunquam rimato, carinam, plus 

 minusve acutam, umbilicalem emittente. 



3. Helix schistostelis, B., n. s. 



Testa perforata, globoso-depressa, tenui, irregulariter striatula, striis 

 confertissimis spiralibus superne decussata, translucente, nitente, 

 pallide cornea ; spira brevi, apice elevatiusculo, obtuso, sutura 

 impressa, marginata ; anfractibus 4\-o\, superne et infra convexi- 

 usculis, ambitu rotundato ; apertura subrotundato-lunari, peri- 

 stomate tenui, recto, acuto, margine columellari subverticaliter 



